Submission #19720153

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Source Code Expand

#include <bits/stdc++.h>
#define pb push_back
using namespace std;
typedef pair<int,int> pii;
const int N=105;
const int maxn=1e4+5;
int dir[maxn],c[N];
pii edge[maxn];
bool vis[maxn];
vector<pii>G[N];
void dfs(int u)
{
    for(int i=0;i<G[u].size();i++)
    {
        pii t=G[u][i];
        int e=t.first;
        if(e<0) e=-e;
        if(!vis[e]&&c[t.second]==c[u])
        {
            dir[e]=(t.first>0?1:-1);
            vis[e]=1;
            dfs(t.second);
        }
    }
}
int main()
{
    int n,m;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        int a,b;
        scanf("%d%d",&a,&b);
        edge[i]=make_pair(a,b);
        G[a].pb(make_pair(i,b));
        G[b].pb(make_pair(-i,a));
    }
    for(int i=1;i<=n;i++)
        scanf("%d",&c[i]);
    for(int i=1;i<=m;i++)
    {
        int a=edge[i].first,b=edge[i].second;
        if(c[a]!=c[b])
        {
            if(c[a]>c[b]) dir[i]=1;//->
            else dir[i]=-1;//<-
            vis[i]=1;
        }
        else
        {
            if(!vis[i])
                dfs(a);
        }
    }
    for(int i=1;i<=m;i++)
        printf("%s\n",dir[i]==1?"->":"<-");
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘void dfs(int)’:
./Main.cpp:13:18: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<std::pair<int, int> >::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   13 |     for(int i=0;i<G[u].size();i++)
      |                 ~^~~~~~~~~~~~
./Main.cpp: In function ‘int main()’:
./Main.cpp:29:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   29 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
./Main.cpp:33:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   33 |         scanf("%d%d",&a,&b);
      |         ~~~~~^~~~~~~~~~~~~~
./Main.cpp:39:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   39 |         scanf("%d",&c[i]);
      |         ~~~~~^~~~~~~~~~~~

Judge Result